Journal of Pure and Applied MicrobiologyVol. 8 No. Special Edition Nov. 2014

Pathological Evaluation and Quantification of Some Seed-Born Fungi of Wheat

A.A. Al-Askar1, Y.M. Rashad2,3 and K.M. Ghoneem4

1Botany and Microbiology Department, Faculty of Science, King Saud University, Riyadh, Saudi Arabia. 2Science Department, Teachers College, King Saud University, Riyadh, Saudi Arabia. 3Plant Protection and Biomolecular Diagnosis Department, Arid Lands Cultivation Research Institute, City of Scientific Research and Technology Applications, Alexandria, Egypt. 4Department of Seed Pathology Research, Plant Pathology Research Institute, Agricultural Research Center, Giza, Egypt.

Received on 06 September 2014 and accepted on 09 November 2014

 

ABSTRACT

Five pathogenic fungi (Alternaria alternata, Bipolaris sorokiniana, B. spicifera, Fusarium avenaceum and F. graminearum) were evaluated for seed discoloration, shriveling, germination and seedling vigor of wheat. Three wheat cultivars (Yecora Rojo, Logame and Sammah), two inoculation times (at anthesis and 12 days later) and two environmental conditions (wet and dry) were used in this investigation. Considerable differences were recorded between the tested fungi for seed discoloration, shriveling, germination and seedling vigor at each treatment. Fungal mycelia were also assessed in wheat grains via estimation of chitin and ergosterol contents. For each fungal species, significant differences between samples were detected. It is evident that visual characteristics of seed provide an imperfect guide to the extent that seed is infected by fungi. Chemical analysis for either chitin or ergosterol, if developed for routine use, could well be helpful in identifying potentially samples on which additional analyses for specific mycotoxins could be carried out.

Keywords : Alternaria alternata, Chitin, Discoloration, Ergosterol, Bipolaris sorokiniana , Seed germination and Shriveling.